2008 CADILLAC CTS radiator cap

How to Check and Add Fluid
Visually check the clutch uid reservoir to make sure the
uid level is at the MIN (Minimum) line on the side of the
reservoir. The hydraulic clutch uid system should be
kept closed and sealed. Do not remove the cap to check
the uid level or to top-off the uid level. Remove the cap
only when necessary to add the proper uid until the level
reaches the MIN line.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains the cooling system and how to
add coolant when it is low. If the engine overheats, see
Engine Overheating on page 5-31.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Allow the warning lights and gages to work as they
should.
Notice:Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs would
not be covered by the vehicle warranty. Always use
DEX-COOL
®(silicate-free) coolant in the vehicle.
5-28

Checking Coolant
The coolant surge tank and pressure cap are located
on the driver’s side of the vehicle, toward the rear of
the engine compartment. SeeEngine Compartment
Overview on page 5-14for more information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the
FROID/FULL COLD line on the side of the surge tank.
Follow the arrow from the top of the tank down the
side to the horizontal mark.
5-30

Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Electric Engine Cooling Fans (Out of View)
B. Coolant Surge Tank and Pressure Cap{CAUTION:
An electric engine cooling fan under the hood
can start up even when the engine is not
running and can cause injury. Keep hands,
clothing, and tools away from any underhood
electric fan.
If the coolant inside the coolant surge tank is boiling,
do not do anything else until it cools down. The vehicle
should be parked on a level surface.
If the engine is warm or hot, the coolant level should be
at or above the FROID/FULL COLD line on the side of the
coolant surge tank. If the engine is cold, the coolant level
should be near the FROID/FULL COLD line on the side of
the coolant surge tank. If it is not, you could have a leak
at the pressure cap or in the radiator hoses, heater
hoses, radiator, water pump, or somewhere else in
the cooling system.
5-34

How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible but
the coolant level is not at the FROID/FULL COLD line on
the side of the coolant surge tank, add a 50/50 mixture of
clean, drinkable water and DEX-COOL
®coolant at the
coolant surge tank, but be sure the cooling system,
including the coolant surge tank pressure cap, is cool
before you do it. SeeEngine Coolant on page 5-28for
more information.
{CAUTION:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They
are under pressure, and if you turn the coolant
surge tank pressure cap — even a little — they
can come out at high speed. Never turn the
cap when the cooling system, including the
coolant surge tank pressure cap, is hot. Wait
for the cooling system and coolant surge tank
pressure cap to cool if you ever have to turn
the pressure cap.
{CAUTION:
Adding only plain water to the cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the
proper coolant mixture will. The vehicle’s
coolant warning system is set for the proper
coolant mixture. With plain water or the wrong
mixture, the engine could get too hot but you
would not get the overheat warning. The engine
could catch re and you or others could be
burned. Use a 50/50 mixture of clean, drinkable
water and DEX-COOL
®coolant.
Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
5-36

{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains eythylene glycol
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
If no coolant is visible in the surge tank, add coolant as
follows:
1. Remove the coolant surge tank pressure cap when
the cooling system, including the coolant surge tank
pressure cap and upper radiator hose, is no longer
hot. Turn the pressure cap slowly counterclockwise
about one-quarter turn and then stop.
If you hear a hiss, wait for that to stop. A hiss
means there is still some pressure left.2. Then keep turning the pressure cap slowly, and
remove it.
5-37

3. Fill the coolant surge tank with the proper mixture,
to slightly above the FROID/FULL COLD line on the
side of the coolant surge tank.4. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. The upper radiator hose is
the top hose coming out of the radiator, on the
passenger’s side of the vehicle. Watch out for the
engine cooling fans.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches the FROID/FULL COLD
line on the side of the coolant surge tank.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Recheck the coolant level in the bottle next time you
use your vehicle to insure the system is full when cold.
SeeEngine Coolant on page 5-28.
5-38

Maintenance Footnotes
(a)Visually inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chafing, etc. Inspect
disc brake pads for wear and rotors for surface
condition. Inspect other brake parts, including calipers,
parking brake, etc.
(b)Visually inspect front and rear suspension and
steering system for damaged, loose, or missing parts or
signs of wear. Inspect power steering lines and hoses
for proper hook-up, binding, leaks, cracks, chafing, etc.
(c)Visually inspect hoses and have them replaced if
they are cracked, swollen, or deteriorated. Inspect all
pipes, fittings and clamps; replace with genuine parts as
needed. To help ensure proper operation, a pressure test
of the cooling system and pressure cap and cleaning the
outside of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Inspect wiper blades for wear, cracking, or
contamination. Clean the windshield and wiper blades,
if contaminated. Replace wiper blades that are worn
or damaged. See Windshield Wiper Blade Replacement
on page 5-57 and Windshield and Wiper Blades on
page 5-117 for more information.(e)Make sure the safety belt reminder light and safety
belt assemblies are working properly. Look for any
other loose or damaged safety belt system parts. If you
see anything that might keep a safety belt system
from doing its job, have it repaired. Have any torn
or frayed safety belts replaced. Also see Checking
the Restraint Systems on page 1-72.
(f)Lubricate all key lock cylinders. Lubricate all body
door hinges. Lubricate all hinges and latches, including
those for the hood, rear compartment, console door, and
any folding seat hardware. More frequent lubrication may
be required when exposed to a corrosive environment.
Applying silicone grease on weatherstrips with a clean
cloth will make them last longer, seal better, and not stick
or squeak.
(g)If you drive regularly under dusty conditions, the
filter may require replacement more often.
(h)Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as high performance operation.
6-8

(i)Drain, flush, and refill cooling system. This service
can be complex; you should have your dealer/retailer
perform this service. See Engine Coolant on page 5-28
for what to use. Inspect hoses. Clean radiator,
condenser, pressure cap, and filler neck. Pressure
test the cooling system and pressure cap.
(j)If using DOT-4 brake fluid only: Drain, flush, and
refill brake hydraulic system at a regular maintenance
service every two years. This service can be complex;
you should have your dealer/retailer perform this service.
See Brakes on page 5-41.
(k)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired
and the fluid level checked. Add fluid if needed.
(l)If you drive regularly under dusty conditions, inspect
the filter at each engine oil change.
(m)Visually inspect belt for fraying, excessive cracks, or
obvious damage. Replace belt if necessary.
(n)If the vehicle has the 3.6L V6 (VIN Code V) engine,
replace the engine air cleaner filter every 40,000 miles
(64 000 km).(o)Check vent hose at transfer case for kinks and
proper installation. Check to be sure vent hose is
unobstructed, clear, and free of debris. During any
maintenance, if a power washer is used to clean mud
and dirt from the underbody, care should be taken to
not directly spray the transfer case output seals. High
pressure water can overcome the seals and contaminate
the transfer case fluid. Contaminated fluid will decrease
the life of the transfer case and should be replaced.
(p)Change transfer case fluid if the vehicle is mainly
driven under one or more of these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as high performance operation or taxi,
police, or delivery service.
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